1. Field of the Invention
The present invention relates to a system for processing information, a device for processing information, and a program. More specifically, it relates to a system for processing information, a device for processing information, and a program, which are arranged so as to inhibit the illegal extension of a utilizing-time limit.
2. Description of the Related Art
In a system that distributes or delivers contents of an image, music, etc. requiring copyright protection through recording media such as an optical disk or a communication path such as a network to play the contents for users, the contents are made to have a watching-and-listening expiry date until which the contents can be reproduced and watched and/or listened to. Thus, the copyright of the contents is protected, and the contents are distributed and delivered to users at a reasonable price.
The judgment of whether it is past the watching-and-listening expiry date has been often relegated to a user. In some cases, a user tried to watch and/or listen to contents, but he or she couldn't do so because it was past the watching-and-listening expiry date.
On that account, a system in which a server manages the watching-and-listening expiry date of contents has been proposed. For example, JP-A-2003-157335 proposes a management device that makes a server manage the dates remaining before the watching-and-listening expiry date, and notifies a user terminal when the remainder reduces below a given level.
However, such server-exclusive management increases a load on the server and requires connection to a network as indispensable. In contrast, in the case of exclusive management by a user terminal, there is a problem such that when a user doctors the time of an internal clock of his or her terminal to extend the watching-and-listening expiry date, the user can commit an injustice such as watching and/or listening to the contents even after the actual expiry date.
As a countermeasure with respect to the foregoing, JP-A-2003-256062 proposes a utilizing-time limit management system in which the watching-and-listening expiry date of a downloaded application is managed by not only a server but also a user terminal, for example.
In the utilizing-time limit management system, the time of the internal clock of the terminal is made to coincide with that of the server by a server control file, whereby the time of the internal clock of the terminal is inhibited from being doctored.